Oil passage structure for transmission
View Patent ↗An oil passage structure for a transmission includes a transmission case having a transmission housing chamber for reserving working oil and housing a continuously variable transmission mechanism therein, and a valve housing chamber for reserving the working oil and housing a valve unit therein. Further, the valve housing chamber housing the valve unit is disposed above an oil level in the transmission housing chamber. Furthermore, the valve housing chamber and the transmission housing chamber communicate with each other through a drain port closed with a drain plug. In demounting of the valve unit, the drain plug is pulled out to open the drain port. Hereby, the working oil can be transferred from the valve housing chamber to the transmission housing chamber, and the valve unit can be demounted without draining the working oil from the transmission case.
1. An oil passage structure for a transmission comprising:
a transmission case;
a transmission housing chamber formed in the transmission case, the transmission housing chamber reserving oil and housing a transmission mechanism therein;
a valve housing chamber formed in the transmission case so as to be disposed above an oil level in the transmission housing chamber, the valve housing chamber reserving oil and housing a valve unit therein;
a drain port formed so as to communicate with the valve housing chamber and the transmission housing chamber; and
a drain plug detachably disposed in the drain port,
wherein oil reserved in the valve housing chamber is drained therefrom by pulling the drain plug out of the drain port, guiding oil from the valve housing chamber to the transmission housing chamber, and reserving oil in the transmission case,
wherein the drain plug includes an oil drain passage having a first port and a second port, the first port being open to the valve housing chamber, the second port being open to the transmission housing chamber, and
wherein excessive amount of oil in the valve housing chamber is guided to the transmission housing chamber through the oil drain passage such that an oil level in the valve housing chamber is maintained at a constant level.
2. The oil passage structure for the transmission according to claim 1 , further comprising:
an oil pump that supplies oil from the transmission housing chamber to the valve housing chamber.
3. The oil passage structure for the transmission according to claim 2 , wherein the drain plug has a first end that projects from an outer surface of the transmission case.
4. The oil passage structure for the transmission according to claim 2 , wherein the drain plug is a fastening bolt for securing the valve unit.
5. The oil passage structure for the transmission according to claim 1 , wherein the drain plug has a first end that projects from an outer surface of the transmission case.
6. The oil passage structure for the transmission according to claim 1 , wherein the drain plug is a fastening bolt for securing the valve unit.